Consulta: creatorFacets:"BIANCHI,NESTOR O"
Registros recuperados: 2
Data/hora: 09/06/2024 05:31:43

Robertsonian chromosome polymorphism of Akodon molinae (Rodentia: Sigmodontinae): analysis of trivalents in meiotic prophase
Provedor de dados: Revista Chilena de Historia Natural
Autores: FERNÁNDEZ-DONOSO,RAÚL; BERRÍOS,SOLEDAD; PAGE,JESUS; MERANI,MARÍA S; LIZARRALDE,MARTA S; VIDAL-RIOJA,LIDIA; BIANCHI,NESTOR O.
Akodon molinae (with 2n = 42-43-44 and an FN = 44) shows a remarkable polymorphism of chromosome 1 in natural and laboratory populations. Specimens 2n = 42, named single homozygotes (SH), have a chromosome pair 1 formed by two large metacentric chromosomes. Specimens 2n = 3, heterozygotes (Ht), have one chromosome 1 and two medium-sized subtelocentric chromosomes, 1a and 1b, which are homologous with the long and short arms of chromosome 1 respectively. Specimens 2n = 44 are double homozygotes (DH), with just two pairs of medium-sized subtelocentric chromosomes, 1a and 1b. Analysis of meiotic metaphases I and II showed that anomalous segregation occurs more frequently in spermatocytes carrying the 1a and 1b chromosomes. This would disturb gametogenesis and...
Tipo: Journal article
Palavras-chave: Akodon molinae; Sigmodontinae; Robertsonian chromosome polymorphism; Trivalents; Synaptonemal complex.
Ano: 2001
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000016

Tracing the origin and geographic distribution of an ancestral form of the modern human Y chromosome
Provedor de dados: Revista Chilena de Historia Natural
Autores: BRAVI,CLAUDIO M; BAILLIET,GRACIELA; MARTÍNEZ-MARIGNAC,VERÓNICA L; BIANCHI,NESTOR O.
We screened a total of 841 Y chromosomes representing 36 human populations of wide geographical distribution for the presence of a Y-specific Alu insert (YAP+ chromosomes). The Alu element was found in 77 cases. We tested five biallelic and eight polyallelic markers in 70 out of the 77 YAP+ chromosomes. We could identify the existence of a hierarchical and chronological structuring of ancestral and derived YAP+ lineages giving rise to four haplogroups, 14 subhaplogroups and 60 haplotypes. Moreover, we propose a monophyletic origin for each one of the YAP+ lineages. Out-of-Africa and out_of-Asia models have been suggested to explain the origin and evolution of ancestral and derived YAP+ elements. We analyse the evidence supporting these two hypotheses and...
Tipo: Journal article
Palavras-chave: YAP+ chromosomes; YAP+ lineages; Y-specific Alu inserts.
Ano: 2001
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000018